If you own the mineral rights, which it appears you do since you kept them when selling the land, then you will receive the benefits of the oil and gas lease, which would include any signing bonus ($ per acre) as well as any royalty payments from the oil and gas should they drill a producing well ...

Great energy source, but it is very dangerous because it is highly explosive. Right now, the best all around (most economical, easiest to produce, easiest to deliver, most abundant) is natural gas. Many coal fired plants are switching to natural gas.